Sulphur Assisted Carbon Mitigation Technology Platform

Sulverenergy Inc. Canadian technology company develops a patented cost-effective suite of technologies for unlocking the widespread utilization of sulphur as an ancillary source of energy. These technologies are realized within the hard constraint of net-zero sulphur oxide gas emission and can be considered to be renewable since sulphur feedstock is fully recycled.

As a technology platform the systems address the cost of electric energy, the key component to the pricing of CCUS, DAC and ASU technologies, and their implementation allows for development of many other applications, processes, scenarios and business models.

The Platform



The subject of this Concept is sulphur fuelled hybrid energy system envisioned as a semi-cycle where CO2 is catalytically activated/converted at moderate temperatures to form intermediate sulphur compound carbonyl sulphide (COS) that subsequently reduces product of sulphur combustion, sulphur dioxide (SO2), to yield carbon dioxide in a form that can readily be captured, and to forming sulphur in a potentially 100% conversion process. The sulphur fuel comprises a gaseous mixture of sulphur vapour (Sn) and sulphur dioxide provided by bubbling oxygen through molten sulphur, industrial proven method called submerged combustion. Furthermore, the system taking advantage of the submerged combustor for the chemical reduction of the sulphur trioxide (SO3) to SO2 in the bed of molten sulphur. In result of that the accompanying the system sulphur thermochemical water-splitting process can efficiently generate hydrogen at significantly lower temperatures (H2SO4 decomposition at ≅400°C.) then current art which carried out the SO2 recovery at temperatures above 800° C., in order to produce a sensible equilibrium conversion.

To overcome the temperature and pressure limitations associated with refractory linings, the water-wall boiler is employed designed with a radiant section, using water-wall tubes, capable of withstanding a very high gas temperature. The theoretical temperature of adiabatic burning of sulphur vapour in oxygen taking in to consideration dissociation process is about 3000-3500°C. Though, burning diatomic sulphur (S2) in pure oxygen in stoichiometric quantities would produce an even higher temperature - more than 5,000°C! 

The homogeneous gas-phase reaction between COS and SO2 in a range of temperature of 700-2000K, pressure of 1-35 atm, and COS:SO2 ratio of 0.6:1 to 2.4:1 is extremely rapid and do not merely yield sulfur and CO2 but a significant amount of CO as well. Therefore, sufficient furnace volume is provided for the cooling of the reaction product to be favourable thermodynamically for re-association of CO and sulphur to yield COS.

Every element in this proposed system has passed beyond the laboratory bench; most are already implemented somewhere at demonstration and/or full industrial scale. Application of this concept for auxiliary power generation is virtually universal and a wide variety of arrangements or modifications to the proposed system are possible.


Opportunities


The Platform provides alternative CCUS infrastructure pathways, which introduce the possibility for many scenarios, particularly in rapid implementation of transportation and storage methods and subsequently creating prospective unambiguous business models, which were hitherto not possible or economically feasible.


Some of these opportunities are:

The global coal-fired power sector is facing a persistently bleak future, with only the prospect of economical technology progress in carbon capture and storage likely to arrest decline. A low carbon future in terms of the stranded assets will have a profound impact on countries, industries and companies. Some studies suggest that globally a third of oil reserves, half of gas reserves and >80% of coal reserves would have to remain unused before 2050 and around $100 trillion of assets could be “carbon stranded”, if not already economically so, for us to have a chance of staying below the 2°C limit. 

As a one of examples the potential solution scenarios for above problem is the implementation of the Hybrid Energy System (HES) for supplemental energy supply for oxygen generation that offers possibility of rapid retrofit of existing coal power plants to oxyfuel systems with the lowest costs compared to other zero emission technologies. The urgency  of  CCS retrofitting  is  further exacerbated  by  the significant  lifetime of  existing power  plants  and the  very  large number  of  plants likely  to  be built  over  the coming decades without CO2 emissions abatement. In  order to  meet  ambitious emission  reduction  levels at  lowest  cost, the  IEA Energy  Technology Perspectives  2010  (ETP 2010)  analysis  suggests that  CCS  retrofit will  play  an increasingly  significant role  until  2030. In terms of retrofit opportunities, the comparably large share of fairly young and large power plants that are installed and operating would suggest a rather large population of power plants to be suitable for retrofitting for CCS. This would arguably offer investors a greater expectation of return on investment, reducing uncertainty and correspondingly lowering the cost of capital. Developing these innovations and delivering such innovations to the European and global markets will strengthen the competitiveness and growth of partner companies and regional economies.

1.            The formation of the tangible value by the CO2 conversion may well stimulate individual companies to collaborate in the development of a carbon capture utilization and/or storage (CCUS) cluster utilizing Conversion Plant as a central hub. Thereby, as illustrated, carbon-emitting facilities (e.g. steel, cement, lime, chemical industry, refining, and fossil power plant) will be able to share a CCUS network infrastructure with, for example, an oxyfuel coal power plant without the necessity for supercritical transportation conditions, while simultaneously addressing hub participants’ various energy-consuming steps in the CCUS process. The ability to share transport and storage network infrastructure is a major component of CCUS cost reduction.

2.            Currently, the preferred techniques for capturing CO2 in cement plants are oxyfuel and post-combustion capture. However, CO2 capture by oxyfuel technology will increase the cement production cost by around 40% (excluding CO2 transport and storage costs) and post combustion liquid solvent scrubbing will increase the cost by around 70-100% (Annual Review 2013, www.ieaghg.org.). The same review concluded that post-combustion CO2 capture (i.e. capture of CO2 from different flue gases of the different combustion processes) in an integrated steel mill could be cost prohibitive for the reasons that it significantly increases the energy demand of the steel mill. The leading use of Oxy‐Blast Furnace (OBF) Technology is one of technology options considered to provide significant reduction of CO2 emissions from iron and steel production based on blast furnace (BF) and basic oxygen furnace (BOF) route. In both above presented cases, the implementation of the Platform for supplemental energy supply for oxygen generation can be the key for viable CCUS for these industries.

3.            Furthermore, Platform present specific opportunities in the case of refineries where the sulphur in petroleum fractions is most frequently found in the form of organosulphur compounds, which are commonly reduced by hydrogen to hydrogen sulphide (H2S) and hydrocarbons. The thermodynamics of some of the reactions of the organic sulphur compounds in the gas phase shows that, above 600 K organosulphur compounds tend to decompose to the reactive form of sulphur (S2), hydrogen, and carbon (C), and above about 800 K formation of carbon disulphide (CS2) from C and S2 becomes favourable. Therefore, with ample CO2 available in a refinery, there is a potential for the formation of COS instead of H2S.

4.             The proposed alternative CO2 transportation infrastructure may include both onshore and offshore elements and the sulphur fueled plant could be located either onshore and/or for example on vessels conveying the CO2 or COS to offshore storage. 

Ships offer flexibility in the CO2 chain, a characteristic not possible with pipelines. Transport by ship can provide flexibility in combining CO2 from several sources, in changing capture sites, storage sites and the transportation routes in a CCS project, an attractive and viable alternative to overcome the limitations imposed by “sink-source matching condition.”  While pipelines require large capital expenditures up front, this is not the case with ships. Ships, on the other hand, have higher operating costs. The largest shipping cost components are electricity and fuel, each accounting for almost 30 % of the total cost. Capital costs only contribute around 28 % of the total shipping cost, compared to more than 70 % for pipeline transport. However, by employing the sulphur for powering ship engines (steam/gas turbine), the logistics of transporting CO2 to offshore storage areas will become economically feasible. 

As the example (labelled as a Case 1 scenario below), liquid COS, delivered by various modes of land transportation to an onshore port facility, is utilized in the process of supplemental power generation distributed by grid to address the various CCUS energy requirements of the participating COS sources and then as “recovered” CO2, liquefied and pressurize (LCO2) is transported by a ship equipped with an onboard injection facility (injection pump, heater) powered by the ship’s engine and operated by ship personnel, to an offshore storage site, to be deliver directly from the ship to the seafloor wellheads of the injection well. Transportation of liquefied CO2 will require a liquefaction plant, loading equipment, as well as access to quay at port. However, no ocean manned platforms with accommodation for workers, and on which CO2 buffer storage tanks will be installed will be required (see: “Preliminary Feasibility Study on CO2 Carrier for Ship-based CCS”, document published on the Global CCS Institute’s website).

In another schematically shown scenario labeled as Case 2, the liquid COS is directly loaded to shuttle transportation vessels and transported to a floating HES hub at the offshore storage site to bypass the step of CO2 liquefaction. This avoids the costly tasks of constructing an LCO2 facility that might face a long series of regulation and permitting negotiations and require a host of new infrastructure on coastline. In this scenario, it is conceivable that the electric power generated by the floating sulphur powered plant can be deliverer to onshore grid by underwater cable. An example of comparable setting is the ship “Prelude” a Shell world first floating LNG plant (FLNG) park at the Australian coast, harvesting the gas from below, but also serving as a factory and store where tankers can pull alongside to load up with LNG.

In a different scenario, shown as Case 3, the liquid COS is used as a means of transportation of sulphur as a method of commodity exchange. Sulphur could then be recovered according to the above-described method resulting in energy generation/power and the CO2 being utilized or sequestered. 

5.             By applying the HES as an energy source for the processes of the production of a hydrogen, methanol and synthetic fuels the purified and captured CO2 from coal combustion and purification systems at great expense can be reused as an industrial chemical feedstock thus contribute to alleviating global CO2 emissions.  

About


As a technological entrepreneur, after years of poring through scientific and technical literature for a versatile, adaptable, state-of-art waste remediation platform, I unexpectedly discovered a fascinating body of work which asserts that global warming, human-induced climate change and other environmental impacts can to some extent be averted through a comprehensive, global effort to use sulphur as an ancillary fuel. Is this notion feasible? 

It is valid to say that aside from carbon and hydrocarbons, sulphur is the only other naturally-occurring material from which energy can be harnessed by combustion. However, the utilization of sulphur for direct heat energy generation is an idea very alien to the power engineering community, which traditionally identified it in power production as an undesirable source of pollution and corrosion.  Sulphur dioxide (SO2), a product of sulphur combustion, when dissolved in water droplets forms acid and when discharged to environment interacts with other gases and particles in the air to form sulphates and other products that can be harmful to people and the environment. Therefore, the combustion of sulphur has been limited to sulphuric acid production. 

Furthermore, in contrast to other liquid fuels, sulfur does not have a light fraction and has a rather high boiling point (450° C). It has a greater heat of evaporation, surface tension, ignition temperature, and specific gravity, but a lower heat of combustion than, for example fuel oil. Sulfur also loses out to fuel oil with regards to conditions for spraying because of the low-pressure drop across the spray jet due to its higher viscosity and surface tension. 

In addition, sulphur vapor constitutes a dissociating system consisting of all molecules from S2 to S8 in temperature- and pressure-dependent equilibria and the sulphur enters the oxidation reaction only as molecule S2, the "diatomic sulphur" a predominant species in sulphur vapor at temperatures above 600° C. Therefore, in the conventional sulphur burner more than 60% of the heat reaction (about 9,400 kJ/kg S) liberated in the combustion of sulphur to sulphur dioxide is theoretically required for preheating the air and sulphur and for evaporation and decomposition of the sulphur. Even so, a sulphuric acid plant produces a prodigious amount of high-level waste heat and nearly all of the high-level waste heat is utilized to produce electricity through a steam turbo/generator.

Be that as it may, there are advantages in sulphur properties that hardly can be ignored. To begin with, is has the capability to attain a very high temperature when burning sulphur in oxygen. The theoretical temperature of adiabatic burning of sulphur vapour in oxygen taking in to consideration dissociation process is about 3000-3500° C.  However, burning diatomic sulphur (S2) in pure oxygen in stoichiometric quantities would produce an even higher temperature - more than 5,000° C! To makes possible to burn sulphur directly in a stream of oxygen sulphur can be evaporate by bubbling oxygen through molten sulphur at a temperature at which the sulphur boils, which ensures maximum evaporation of sulphur. This industrial proven method is called submerged combustion. 

In addition, sulphur dioxide (SO2), if dry, is not corrosive and, in contrast to carbon dioxide, can be relatively easily reduced by carbonyl sulphide (COS) to yield carbon dioxide (CO2) in a form that can readily be captured, in addition to forming sulphur in a potentially 100% conversion process.  Lastly, if the sulphur compound COS is generated by conversion of CO2 from power plants, industrial facilities or the atmosphere and utilised as an intermediate a hybrid correlation energy system can be designed whereby energy is obtained from two different prime sources, such as coal and sulphur, without detrimental atmospheric impact of sulphur oxides. It is important to note that CO2 conversion is a proven commercial process. Also, every element in this proposed system has passed beyond the laboratory bench; most are already implemented somewhere at demonstration and/or full industrial scale.

How did the platform concept originate?

As a technological entrepreneur I committed myself to the specific technology which can provided a versatile, adaptable, state-of-art waste remediation platform for processing most common waste stream within one integrated system. To provide a versatile, adaptable, state-of-art waste remediation platform I obtained Battelle Memorial Institute license of vitrification technology to effectively treat and dispose of municipal waste materials without creating undue environmental contamination. In the same time, I initiates research on application vitrification technology for treatment of phosphogypsum (PG), a by-product of processing phosphate ore into fertilizer with sulfuric acid. It is radioactive due to the presence of naturally occurring uranium and radium in the phosphate ore. With two of US Department of Energy's (DOE) Pacific Northwest National Laboratory (PNNL) vitrification technology leading researches, Chris Chapman and Richard Peters, I initially obtained research grants from Florida Institute of Phosphate Research (FIPR) to investigate the manufacture of vitrified glass products from PG. Manufacture was successfully demonstrated on a pilot scale; however, the economics of the process would not justify commercial implementation due to the energy requirements of the process.

A subsequent grant from FIPR addressed the energy issue by attempting to recover sulphur in the process that could be utilized to drive the process. A process was developed whereby energy co-produced in sulfuric acid production could be substantially increased. During these investigations it became apparent that the energy values available through sulfur combustion are potentially enormous. Current energy production from sulfur combustion is limited to co-production at sulfuric acid production facilities, which provides sufficient energy to power the phosphate fertilizer production complex. Presently the only large scale industrial practice that can utilize sulphur dioxide is in the production of sulphuric acid. In fact, more than 90% of the world’s consumption of sulphur is dedicated to the production of sulphuric acid, and the vast majority of this is produced by the global phosphate fertilizer industry which employs sulphuric acid in the acidulation of phosphate rock for phosphoric acid production. 

There are vast resources of sulphur, both natural, and by-product, available in the world beyond the current requirements of industry. It was thought that if an alternative means of dealing with the products of sulphur combustion could be found, energy derived through sulphur combustion could be freed from its dependence on sulphuric acid production, thereby unlocking the key to the widespread utilization of sulphur as a source of energy.

PUBLICATIONS

Development of Process to Manufacture Glass/Glass-Ceramic Products from Phosphogypsum.  Chris Chapman, Bogdan Wojak, and Richard Peters; with P.K. Bhattacharjee - Vitrification International Technologies, Inc.; prepared under a grant sponsored by the Florida Institute of Phosphate Research, Bartow, Florida.  FIPR Publication no.01-153-221.  April 2006.

Development of Process to Manufacture Glass Products from Phosphogypsum.  Chris Chapman, Richard Peters, and Bogdan Wojak – Vitrification International Technologies, Inc.; prepared under a grant sponsored by the Florida Institute of Phosphate Research, Bartow, Florida.  FIPR Publication no. 01-153-163.  April 1999.

PATENTS

Sulphur-Assisted Carbon Capture and Utilization (CCU) Processes and Systems, patents: CA2931223, US9802153.  

Sulphur-Assisted Carbon Capture and Storage (CCS) Processes and Systems,  patent: CA2898519, US10066834.

Methods and Systems for Transporting Sulphur as a COS, patent: CA2791963.

Method and Systems for Sulphur Combustion, patents: CA2813125, CA2700746, EP2203680.

Gas Turbine Topping in Sulfuric Acid Manufacture, patents: CA2663131, EP2069233.

Gas Turbine Topping Device in a System for Manufacturing Sulphuric Acid and Method of Using Turbine To Recover Energy in Manufacture of Sulphuric Acid, patents: CA2639747, US7543438.


ACKNOWLEDGEMENTS


Sulverenergy gratefully acknowledges the generous funding from Florida Industrial and Phosphate Research Institute  (FIPR) and Thomas Dutcher who has forty-seven years of project engineering, engineering design, construction management experience, and as a successful business owner. His work includes over twenty years of incineration and waste-to-energy engineering development.


Advisory and literature review support provided by an exceptionally knowledgeable and experienced team of dedicated specialists, Mike Lloyd and Gary Albarelli of Florida Industrial and Phosphate Research Institute is also greatly appreciated.


 The chemistry, thermodynamic and energy/mass balances for the method of sulphur combustion as the kinetic simulation of the reduction of sulphur dioxide (SO2) by carbonyl sulphide (COS) have been performed by Dr. Kunal Karan of the Department of Chemical Engineering of Queens University in Kingston, Ontario.


A special thanks to Dr. Laszlo T. Nemeth, co-inventor of the CO2/COS conversion process for several thoughtful and stimulating discussions of this work. It is noteworthy that Dr. Nemeth had the very fortunate opportunity to work as a post-doctorate with Nobel Laureate, Professor George Olah, the initiator of the idea of a Methanol Economy, which the technologies proposed by Sulverenergy attempt to realize.


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