Processes for producing hydrocarbon products

Abstract

The present invention relates to processes for producing industrial products such as hydrocarbon products from non-polar lipids in a vegetative plant part. Preferred industrial products include alkyl esters which may be blended with petroleum based fuels.

1 . A process for producing an industrial product, the process comprising the steps of:
 i) obtaining a vegetative plant part having a total non-polar lipid content of at least 10% (w/w dry weight),   ii) either
 a) converting at least some of the lipid in the vegetative plant part of step i) to the industrial product by applying heat, chemical, or enzymatic means, or any combination thereof, to the lipid in situ in the vegetative plant part, or 
 b) physically processing the vegetative plant part of step i), and subsequently or simultaneously converting at least some of the lipid in the processed vegetative plant part to the industrial product by applying heat, chemical, or enzymatic means, or any combination thereof, to the lipid in the processed vegetative plant part, and 
   iii) recovering the industrial product,   
       thereby producing the industrial product. 
     
     
         2 . The process of  claim 1 , wherein the step of physically processing the vegetative plant part comprises one or more of rolling, pressing, crushing or grinding the vegetative plant part. 
     
     
         3 . The process of  claim 1 , which prior to step ii) further comprises the steps of:
 (a) extracting at least some of the non-polar lipid content from the vegetative plant part as non-polar lipid, and   (b) recovering the extracted non-polar lipid.   
     
     
         4 . The process of  claim 3 , wherein
 (i) the extracted non-polar lipid comprises triacylglycerols, wherein the triacylglycerols comprise at least 90% (w/w) of the extracted non-polar lipid, and/or   (ii) the extracted non-polar lipid comprises free sterols, steroyl esters, steroyl glycosides, waxes or wax esters, or any combination thereof.   
     
     
         5 . The process of  claim 3 , wherein step (a) uses an organic solvent. 
     
     
         6 . The process of  claim 3  which comprises one or more of
 a) recovering the extracted non-polar lipid by collecting it in a container, 
 b) one or more of degumming, deodorising, decolourising, drying or fractionating the extracted non-polar lipid, 
 c) removing at least some waxes and/or wax esters from the extracted non-polar lipid, and 
 d) analysing the fatty acid composition of the extracted non-polar lipid. 
 
     
     
         7 . The process of  claim 3  in which the volume of the extracted non-polar lipid is at least 1 litre. 
     
     
         8 . The process of  claim 1 , wherein the industrial product is a hydrocarbon product such as fatty acid esters, preferably fatty acid methyl esters and/or a fatty acid ethyl esters, an alkane such as methane, ethane or a longer-chain alkane, a mixture of longer chain alkanes, an alkene, a biofuel, carbon monoxide and/or hydrogen gas, a bioalcohol such as ethanol, propanol, or butanol, biochar, or a combination of carbon monoxide, hydrogen and biochar. 
     
     
         9 . The process of  claim 1 , wherein the vegetative plant part is an aerial plant part or a green plant part. 
     
     
         10 . The process of  claim 9 , wherein the vegetative plant part is a plant leaf or stem. 
     
     
         11 . The process of  claim 1 , further comprising a step of harvesting the vegetative plant part from a plant with a mechanical harvester. 
     
     
         12 . The process of  claim 11 , wherein the vegetative plant part is harvested from the plant some time between about the time of flowering of the plant to about the time senescence of the plant has started. 
     
     
         13 . The process of  claim 1 , wherein the vegetative plant part comprises a total non-polar lipid content of at least about 15% (w/w dry weight). 
     
     
         14 . The process of  claim 1 , wherein the vegetative plant part comprises a total TAG content of at least about 11% (w/w dry weight). 
     
     
         15 . The process of  claim 1 , wherein the vegetative plant part has one or more or all of the following features:
 i) oleic acid comprises at least 19% of the total fatty acid content in the non-polar lipid in the vegetative plant part,   ii) palmitic acid comprises at least 20% of the total fatty acid content in the non-polar lipid in the vegetative plant part,   iii) linoleic acid comprises at least 15% of the total fatty acid content in the non-polar lipid in the vegetative plant part, and   iv) α-linolenic acid comprises less than 15% of the total fatty acid content in the non-polar lipid in the vegetative plant part.   
     
     
         16 . The process of  claim 1 , in which at least some of the lipid is converted to the industrial product by chemical means, wherein
 i) the chemical means comprises reacting the non-polar lipid with an alcohol, optionally in the presence of a catalyst, to produce alkyl esters, and   ii) optionally, blending the alkyl esters of step i) with petroleum based fuel.   
     
     
         17 . The process of  claim 16 , wherein the alkyl esters are methyl esters. 
     
     
         18 . The process of  claim 1 , wherein the industrial product is synthetic diesel fuel and the process comprises:
 i) converting the non-polar lipid in the vegetative plant part, or the processed vegetative plant part, to a syngas by gasification, and   ii) converting the syngas to the synthetic diesel fuel in a process comprising using a metal catalyst or a microbial catalyst.   
     
     
         19 . The process of  claim 1 , wherein the industrial product is a biofuel which is bio-oil or biogas, and the process comprises converting the non-polar lipid in the vegetative plant part or the processed vegetative plant part to the bio-oil by pyrolysis, or to the biogas by gasification or anaerobic digestion.