Syngas
Biofuels Energy, Inc.
Home About Us Biomass Myth Glycerol to Syngas Corporate Contact Us Search The Company Changing the World
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Home About Us Biomass Myth Glycerol to Syngas Corporate Contact Us Search The Company Changing the World |
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Ethanol Biofuel Is Energy Inefficient and Builds “Moonshine” Deposits in the Combustion Engines or Fuel Cells All the current and projected economically sound processes of making gas extenders ethanol or butanol are based on Glycolysis, a biochemical pathway where the production of gas extenders is accompanied by significant co-production of CO2. Each mole of six carbon sugar glucose provides synthesis of two moles of ethanol or one mol of butanol along with two moles of CO2. The five carbon sugars, pentoses (biomass-to-biofuels process), provide 1.67 moles of ethanol or 0.835 moles of butanol and 1.67 moles of CO2. In industry, recovery of raw material carbon as fuel gas extenders ethanol or butanol does not exceed 43 - 45% of the original carbon of sugar (the best case scenario developed is sugars + pretreated hydrolysed biomass to release extra sugars from the biomass), as the balance carbon is divided between the cell mass carbon (~3%) and the CO2. Nearly 34 % of raw material carbon is CO2 is either emitted to the atmosphere during the manufacture, or disposed by some costly means. Present economical ways of CO2 disposal include compression for sale in bottles for food industry needs, use of compressed CO2 as a solvent for a number of applications (for example, dry cleaning), or as a coolant in ultra-low temperature freezers, or most commonly pumping of compressed CO2 to "mature" oil wells via established pipelines to enhance oil recovery. The CO2 disposal increases biofuel manufacturing costs dramatically. Chemical impurity: Fuel grade of available commercially gas extenders ethanol or butanol means only high level of dehydration to ensure blending with gasoline. It does not mean chemical purity from acids, esters, ketones, aldehydes and other by-products. The content of such impurities varies depending on the raw material and technology used. Established fuel ethanol and proposed butanol production from low-cost sugars-containing raw material supplies fuel extenders with substantial impurities of different molecular weight. Such impurities are already present in contaminated raw material. Additional impurities are produced during non-sterile commercial scale sugar-based (including sugars from biomass) fermentations. High molecular weight impurities form deposits and cause corrosion in combustion engines or fuel cells (increase of maintenance and repair costs), not to mention pollution of the environment. Syngas Synthesis gas (syngas) is produced from any carbon containing material using the gasification technology established more than a century back. Essential components of syngas obtained by oxygen-blown gasification are CO, hydrogen (H2) and small amounts of CO2 with or without impurities such as nitrogen and nitrogen oxides, some mercury, sulfur oxides/hydrogen sulfide, CxHy, steam, etc, depending on the carbon source used. Syngas from coal or petroleum coke produced in oxygen blown gasifiers has up to 66 - 67% of CO, 31 - 33% of H2, and CO2 the balance after the syngas is cleaned up for chemical synthesis (gas-to-liquids chemical catalysis). In these environmentally clean days, syngas is a perfect clean burning fuel used for electric energy generation with approximately half of the natural gas heating value to substitute natural gas, and for chemical synthesis based on chemical catalysis to produce variety of chemicals at the major chemical companies not limited to Eastman Chemical Co., GE, Celanese Chemicals, Sasol, Range Fuels and others, including the manufacture of fuel gas extenders ethanol or butanol. Powering gas turbines or fuel cells makes syngas a valuable fuel for the electric power generation (Polk Energy Station in Florida). The Wabash River Power Generating Plant can generate 292 MW of electricity, and 262 MW of which are supplied to the electric grid, making it one of the world’s largest single train gasification combined cycle plants operating commercially.
Wabash River Power Generating Plant, IN Chemical synthesis of some compounds/commodity chemicals from purified syngas requires expensive catalysts based on noble/rare metals, and does not provide enough chemical selectivity so typical for fermenting syngas biological catalysts, which alone ensure the manufacture of only chemically pure target products - biofuel gas extenders ethanol or butanol. For all purposes, syngas has to be used in situ. Syngas manufacture offers the benefits of co-generating inexpensive heat when the produced at high temperature syngas is cooling down for low temperature fermentation. The released heat is recovered using commercial heat exchangers in integrated energy preserving process (the so-called Integrated Gasification Combined Cycle, or IGCC). Large scale commercial gasification utilizes coal or petroleum coke. In "Northern" areas, such as some parts of Canada, Norway, North of Pacific West in the US, the growth rate of natural forest exceeds annual wood processing capacity 8 times or more. Gasification of chipped wood is an attractive option in these areas. In addition to the traditional raw materials to make syngas via gasification of coal, petroleum refinery waste or steam reforming reaction of natural gas or methane developed in biogas reactors, another contemporary syngas raw material source is glycerol, a byproduct of booming bio-diesel manufacture. The resulting syngas is rich in hydrogen if 50:50 weight ratio of steam to glycerol ratio is maintained. Rich in hydrogen syngas is the most favorable for syngas fermentations by acetogens. Microorganisms-Biocatalysts Chemical catalysis is a complex process requiring preliminary syngas "clean-up". Biocatalysis, while still a multi step process, looks and works like a single-step catalysis since all the chemical reactions are performed inside microbial cells. Microorganisms-biocatalysts fermenting syngas to biofuels, isolated and further selected using our proprietary technology, are naturally resistant to syngas impurities such as nitrogen and nitrogen oxides, some mercury, sulfur oxides/hydrogen sulfide. In some cases microbial catalysts may be easily mutated using our proprietary mutation technology to withstand elevated amounts of syngas impurities. Mutants are also used to tolerate butanol as the target final product at production levels of 5% and up in the “beer” liquid (fermentation broth). Gasification Gasification is the process of heat treatment of any carbonaceous (carbon-containing) material under the controlled oxygen input in the presence of steam. It is performed at high temperatures in excess of 1,800 - 2,000oF. Microbial biocatalysts utilize syngas at moderate temperatures not to exceed 120oF for our proprietary fermentation technology. The heat energy during syngas cooling down to below 120oF is recovered using heat exchange process. The released heat in the form of steam powers turbines to generate electric power or for other endothermic processes. Combining of gasification and the use of the recovered thermal energy at the gasification site ensures the source of inexpensive heat and electric energy for manufacture of biofuels and chemicals. Gasification Types by the Oxygen Supply Based on the oxygen supply, two major gasification types are currently commercialized: oxygen-blown and air-blown gasification. Oxygen-blown gasification requires very energy consuming cryogenic oxygen plant prior to the gasification plant to separate oxygen from the air to blow through gasifiers. Oxygen plant adds may almost triple the syngas manufacturing cost. Air-blown gasification is similar to the above plus retains nitrogen up to 46% of the total syngas composition however maintains the CO at ~31%, H2 ~ 16%, and CO2 at up to 3.6%, thus definitely requiring our proprietary patented bioreactor design to strip out the balance N2 to vent from the bioreactor during fermentation of CO, H2, and CO2. Peabody Energy Corporation, the largest in the Nation source of PRB coal (Powder River Basin coal), located on the border of the states of WY and MT, has gasification plants built at coal mine sites. The PRB coal resources exceed several billion tons of the coal available for surface mining, and the coal prices have not been changing much over the past 30+ years. For the pet coke, Eastman Chemical Company plans to build a major in the Nation gasification facility in Beaumont, TX, and make it operational by the end of the year 2011 (Eastman Chemical Company). Heat and Electricity Co-Generation During Conventional Gasification (IGCC) Since fermentors operate at below 120oF, significant amounts of heat may be recovered from syngas using standard heat exchangers during the cooling down from in the excess of 2,000oF to below 120oF. Such inexpensive heat may be used directly for distillation (ethanol) or evaporation-concentration (butanol) and for any other energy-consuming steps via powering steam turbines or directly. The resulted electric energy is available at the rate of $0.03 - 0.06 per kW/h, with the balance of unused electric energy sold to the grid. Oxygen-blown gasification allows recovery in heat exchangers of up to 71% of the original fuel heat energy (typically referred as BTU, British Thermal Units). The same number for air-blown gasification is up to 35%. There are reports on advances in plasma-mediated gasification of carbonaceous material. Incerneration is a progressive way of waste management. However, incerneration does not provide source of inexpensive heat and electric energy during syngas cooling down leaving up to 16% of carbonaceous material intact as compared with almost 99% its conversion when perfectly tuned traditional gasification is used. Some amounts of corrosive hydrochloric acid are produced during incerneration. Contact Information
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