Recipient Organization
TDA RESEARCH, INC.
12345 WEST 52ND AVENUE
WHEAT RIDGE,CO 80033
Performing Department
(N/A)
Non Technical Summary
The production of turpentine in the U.S. exceeded 301,000 tons in 2004 (Romney 2004) and the production of resin acids exceeded 800,000 ton in 2003 (Romney 2004), which also includes the production from directly tapping trees (e.g., gum turpentine, gum rosin). There is growing demand for bio-plastics (non-petroleum derived polymers); for example Pepsi announced it will be using bio-plastic bottles in all their products by 2018. Coca Cola is expected to follow suit, which will generate commercial interest for inexpensive bio-materials that can provide an alternative to bio-ethanol (expensive for a raw material). TDA believes that this is an emerging market with substantial growth potential. Worldwide production of pinenes is 0.33 million tons per year (FAO, 2011); 70% of this comes from CST produced as chemical pulping by-product. A major consequence of the pulping process is that sulfur compounds are introduced into the CST, which substantially degrades the quality of the pinenes. Sulfur compounds not only reduces the potency of the pinene flavor (as they usually smell bad), but also, they poison the noble metal and metal oxide catalysts used to in the fine chemical synthesis process (such as the Pt-based catalysts used in alpha pinene to beta pinene isomerization). Sulfur remaining in the fine chemicals are also undesirable. For example, sulfur imparts foul odors to the bio-plastics. Therefore, these terpene fractions must be desulfurized to increase value of the bio-products and the specialty chemicals that are made from them. The proposed outcome of this project is a sulfur sorbent capable of removing sulfur compounds from alpha pinene and other derivatives of turpentine (terpenes etc.). These pure fractions will generate increased market value for a range of applications, and their purity will make them suitable feedstocks for catalytic conversion to specialty chemicals
Animal Health Component
30%
Research Effort Categories
Basic
10%
Applied
30%
Developmental
60%
Goals / Objectives
Turpentine is a by-product of the Kraft wood pulping process, and its derivatives (e.g., terpenes such as alpha pinene) are used as fragrances in a number of commercial products ranging from cosmetics to detergents. They can also be, and are, catalytically transformed into valuable chemicals by hydrogenation, oxidation and isomerization reactions. However, turpentine and its derivatives contain small but significant quantities of sulfur, which degrades the potency of pinenes used as fragrances. Sulfur is also a highly potent catalyst poison for the precious metal and metal oxide catalysts used in the conversion processes. TDA Research Inc. proposes to develop a new, high capacity, regenerable sorbent to remove sulfur species from alpha pinene and potentially from other terpene derivatives. The sorbent will be capable of reducing the sulfur concentration of the pinene to sub ppm levels to improve product quality and to be able to meet the cleanliness requirements of downstream catalytic conversion processes that convert alpha pinene into value added chemicals.
Project Methods
Conventional desulfurization techniques such as fractionation, absorption, hypochlorite treatment, and treatment with metals and activated carbons have not been very effective at desulfurizing CST and pinenes. Fractionation and absorption leaves a significant amount of sulfur in the pinene. Hypochlorite treatment (US Patent 3778486, US Patent 3660512 and US Patent 3778485) introduces chlorinated hydrocarbons that must in turn be removed by distillation and purification, greatly increasing the costs. The use of hydro-desulfurization catalysts (such as Co-MoS2) has been investigated, but these resulted in unselective hydrogenation of the pinene fractions, changing composition and degrading it (EP 243238 and EP 267833). Activated carbon-based physical adsorption processes do a good job of removing the sulfur and preserving product's integrity (US 3778486, FR 2243246), however, the sorbent replacement cost associated with one-time use activated carbon beds makes the process cost prohibitive. Therefore, more efficient low-cost sulfur removal methods which do not change in the composition of the turpentine still need to be developed. TDA Research proposes to develop a low-cost, high-capacity regenerable sorbent that can remove all the organic sulfur species from alpha pinene and other terpenes. Our sorbent uses a highly dispersed metal phase that removes sulfur compounds via chemical complexation. The active adsorptive phase will be highly dispersed on a mesoporous support that has large pores to allow the large organic sulfur compounds, (such as the dimethyl disulfide, propyl disulfide along with various mercaptans and alkyl thiophenes) to access the pores and adsorb over the metal sites. The proposed sorbent will be distinctly different in composition and in performance (based on the preliminary test results) than commercially available materials. We will use a state-of-the-art, fully-automated sorbent testing apparatus to assess sorbent performance. We will extract samples from the treated and untreated terpene fractions to assess the clean-up capability of the sorbent.