Sustainability

Oil, Gas and Biofuels

Oil, Gas and Biofuels

Lime, limestone, dolomite and clay find many applications in the oil, gas and biofuels industries. They are used in various steps of the industrial process:  as key ingredients to control the density (limestone and dolomite), pH (lime) or viscosity (clay) of drilling muds, and even to refine biofuels. All of these applications require strictly-controlled chemistry, particle size and reactivity.

The products we supply to these markets meet required industry regulations. Some of our solutions represent recognized global standards, as is the case of SeaMudTM, the preferred viscosity-control agent for salted water drilling mud.

Oil, gas and biofuels represent a large share of energy production worldwide. From extraction to refining (from which final products such as gasoline are obtained), specific solutions are needed to meet an ever-growing demand. On top of this, there are tight environmental regulations that must be met and increasingly complex technologies employed due to the rise of unconventional oil sources. Therefore many mineral products used in these processes must meet highly-demanding specifications.

Oil and gas drilling

Our products are used in oil and gas drilling in a number of ways:

  • Calcium carbonate increases the density of drilling fluids. This counteracts pressure in relatively shallow formations. It can be used in either water- or oil-based mediums. 
  • Our limestone products feature low levels of acid insolubles making them useful in sealing permeable formations during periods of workover. Limestone sizes can be customized to fit the liquid medium and formulation. 
  • Limestone particle size is controlled to prevent settling. A broad mixture of interlocking particle sizes allows the material to serve as a bridging medium.
  • Specialized clay products are used in drilling muds to control viscosity and to improve the stability of the well bore. Lhoist’s exclusive sepiolite, SeaMudTM is the industry standard viscosity modifier for salt water drilling and saline environments. We also offer a line of proprietary clay products and engineered blends for fresh and salt water drilling applications.
  • Hydrated lime is used in drilling and circulating fluids to adjust downhole pH and to control H2S and CO2. It is also very helpful in the treatment and recycling of recovered fracking water to adjust pH and to precipitate metals and other solids. On-site recycling reduces both the amount of discharged water and the demand for fresh water, as well as decreases the associated vehicle traffic required to remove and replenish these materials. Quicklime and hydrated lime slurries are used to stabilize soils in drilling sites and pads in locations where stability of plastic soil is an issue.

Biofuels

The most common biofuels are bioethanol and biodiesel. The transportation sector accounts for 98% of total product consumption. Global production is expected to rise in the future, due to:

  • recent regulations
  • government policies on energy independence
  • public subsidies
  • high demand.

US, Brazil and EU are key regions, yielding over 75% of the biofuel available worldwide. Current global production uses first-generation technologies that rely on raw food materials (sugarcane, sugar beets, corn, maize, oilseeds). Advanced second-generation technologies are emerging fast and will make a significant contribution in the medium and long terms. They use raw non-food materials, such as cellulosic biomass from agriculture and forest waste.

Depending on the first-generation technology employed, lime can be added during the production process for by-product valorization and for effluent treatment. We have developed a broad range of lime products which coupled with our expertise creates the required lime slurry in a sustainable way, saving both water and energy.

Bioethanol from sugarcane

Our customized lime and dolime solutions aid the washing of sugarcane, the treatment of sugar juice and the valorization of by-products.

Sugarcane washing

When harvested, raw sugarcane is typically covered with wax, mud and oxides. These impurities are removed by washing. Lime is added to increase the alkalinity of the water to prevent corrosion of the crushing equipment.

Sugar juice treatment

Lime is used to reduce high phosphorus levels in sugar juice. The juice is then fermented to produce bioethanol.

Valorization of by-products

Bagasse and vinase are by-products of this industry. Bagasse is used as a source of energy and as feedstock for second-generation biofuels. Vinase is produced during fermentation. By adding specific lime products, it can then be used in agriculture as a soil amender.

 Bioethanol from sugarcane is mainly produced in Brazil.

Bioethanol from sugar beet

We have developed specific lime products for the treatment of sugar beet juice and its concentration before bioethanol can be produced.

Treatment of sugar beet juice

Sugar beet is processed in a similar way to sugarcane. Bioethanol is produced by mixing fresh sugar juice, molasses and syrups. Raw sugar beet is cleaned before juice extraction. Lime is added to the washing water to raise pH and limit odors.

Concentration

Lime is added to the fresh sugar juice to obtain concentrated syrup before storage and later conversion into bioethanol.

Europe is home to the greatest production of bioethanol from sugar beet.

Bioethanol from maize

Distiller grains soluble (DGS) can be valorized as animal feed using our customized lime solutions.

Maize is transformed into ethanol in three steps. After wet milling, hydrolysis is carried out in water using yeast and in conditions which are acidic enough to produce the glucose that is then fermented to make ethanol. The resulting ethanol is distilled. No alkali is needed during these steps.

Valorization of DGS (Distiller grains soluble)

A vegetable residue and DGS are the two major by-products from this industry. Vegetable residues are generally burnt for energy recovery or used as animal feed. DGS contains lipids, proteins and fibers. Combined with lime and limestone products, they are highly valuable as animal feed and in animal diets.

Most bioethanol from maize is made in US.

Biodiesel from oilseed

The valorization of oilcake from oilseed extraction is possible using our dedicated lime products.

Oil seeds are cold pressed using organic solvent (n-hexane). The extracted oil is refined by a series of distillations and chemical treatments using caustic soda to remove fatty acid by-products.

The resulting vegetal oil is subject to a reaction of transesterification to produce biodiesel.  Lime is an alternative cost-effective reagent to replace caustic soda in this process.

Valorization of oilcake

Oilcakes (from oil extraction), fatty acids, free fatty acid (FFA) (from oil refining) and glycerin (from transesterification) are the most important by-products from this industry. Animal feed and animal diets benefit from the proteins and fibers found in oilcakes when combined with lime and limestone products.

Biodiesel from oilseeds is principally manufactured in Europe.  

Biogas

Hydrated lime is used in the production of biogas to stabilize the process and optimize the gas yield.

Biogas units do not always run stably, particularly if the quality and type of substrates used change. This is especially true if the new substrates have a low buffer capacity and when the unit is overfed. In these cases, the pH of the fermentation substrate may fall. An efficient biogas unit is one that offers a stable fermentation process using substrates with a high buffer capacity. There should also be no downtime, even when different substrates are used. Only then can a continuously high gas yield be achieved.

Stabilizing the process

Regular usage of hydrated lime in biogas units that are often fed with the most varied fermentation substrates stabilizes the buffer capacity and prevents a sharp drop in pH even with peak loads.

Optimizing the gas yield

Hydrated lime ensures stable operation in all phases of the fermentation process. It thereby helps secure a regular and high gas yield in the biogas unit. The amount of methane in the gas mixture is increased and leads to better technical usability.

CaO added via the hydrated lime remains in the fermentation substrate and serves as field fertilizer later on.