The Catalyst Review May 2019 - 1

INDUSTRY PERSPECTIVES

The views expressed are those of the individual author and may not reflect those of The Catalyst Review or TCGR

Bio-Based Lubricant Base-Oils:
Tuning Synthesis to Meet Market
Desirability
The global lubricant market size was $146 billion in 2018 and is projected to reach $166 billion by 2023 with a compound annual
growth rate (CAGR) of 2.6% (BCC Research 2018). The market is segmented into the following broad categories: automotive
lubricants, industrial lubricants, metal-working fluids, process oil, marine lubricants and grease (Figure 1a). Figure 1b depicts the
market size by region. Product quality in all sectors has changed significantly because of the growing demand for high-performance
lubricants by consumers and equipment manufacturers. Fast paced technological advancement towards transformative modular
equipment and engine design for improved energy efficiency, fuel economy, and environmental sustainability are major drivers for
this market shift.
Conventional lubricants are either mineral or synthetic
- depending on the use of base-oil. Base-oils constitute
the major component (75-90 wt%) followed by various
additives, e.g., antioxidants, pour point depressants,
viscosity index improvers, corrosion inhibitors, and antiwear agents. The additives are carefully formulated
with base-oils to achieve desired specifications (e.g.,
viscosities, viscosity index, pour point, oxidative
stability, acid number, rust prevention and corrosion,
friction).
Although mineral lubricants account for ~78% of the
total global lubricants (Figure 1c), their overall CAGR is
lower than that of synthetic ones (Figure 1d) because
of the market shift. The CAGRs of both lubricants vary
widely by region (Figure 1d) depending on the local
supply chain and environmental regulations. Some
synthetic lubricants qualify as Environmental-Acceptable
Lubricants (EALs) based on their bioaccumulation data.

Figure 1. Global lubricants market size by (1) application, (b) region, (c) type,
and (d) CAGR by region. Figure (e) depicts global bio-lubricant market by
region. Source: BCC Research 2018. CAGR = compound annual growth rate.

Bio-based lubricants represent over 3% of total global lubricant sales (about $6 billion) (Figure 1c) and possess higher market growth
than mineral base-oils lubricants (Figure 1d). They have received significant market acceptance as EALs in recent years because of
the use of sustainable feedstocks and bio-preferred products as per USDA (United States Department of Agriculture). Although AsiaPacific is the largest consumer of bio-lubricants (Figure 1e), the consumption ratio of bio-lubricants to total lubricants is significantly
higher in Europe because of its union's REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) regulation.
Triglycerides and fatty acids-derived EALs received attention when they got introduced; however, their poor oxidation stability at
high temperatures makes them unsuitable for most industrial applications where high risk of environmental exposure of petroleum
lubricants exists. The synthesis of these ester-based lubricants requires chemical modification of triglycerides or fatty acids through
esterification/ transesterification, acyloxylation, epoxidation and hydrogenation. Lubricant base-oils formed by epoxidation of double
bonds of triglycerides followed by epoxide transformation have poor cold fludity for low temperature applications. Hydroformylation,
alkylation and acylation, ene-reaction, and acyloxylation can improve cold-fluidity but poor process economics remain a challenge.
The ester groups are prone to hydrolysis and their deployment to marine applications is limited.
Novvi LLC has recently introduced a new class of bio-based base-oils, which are structurally similar to petroleum-derived synthetic
poly-α-olefin base-oils. Novvi's base-oils, synthesized from bio-based Farnesene and petroleum-derived linear-α-olefin via a coupling
reaction, have received significant interest because of their acceptable oxidation stability.
Researchers in the Catalysis Center for Energy Innovation have recently introduced a synthetic strategy, where alkylfurans, derived
from non-food biomass, and aldehydes, produced from natural oils or biomass, were catalytically coupled and hydrodeoxygenated
to produce base-oils with structurally similar to commercial poly-α-olefins (Liu et al. 2019). This strategy enabled the synthesis of
base-oils with varying number of carbons, branching carbon chain-length, distance between branches, and functional groups. The
continue on page 6
The Catalyst Review

May 2019

The Catalyst Review May 2019

Table of Contents for the Digital Edition of The Catalyst Review May 2019